I'm not really sure how I got the IP address to work, and I've been kind of just messing with the DNS numbers, but I still keep failing the DNS text on my xbox live. I've turned the modem off and on, taken the power supply off and on, restarted the computer, blah blah blah. I don't really know what to do. I was hoping someone else has had this similar problem, and could help me out. My modem is a Motorola SB5120 from Comcast. Thank you soo much in advance.
best thing to do is start from scratch and go through all the steps.
1. on PC go to START->RUN-> then type cmd
2. when you get the command prompt type ipconfig/all
3. now write down all of the info there as you will need it
4. no go to the Xbox and input the information into the network settings.
5. The IP can be anywhere in your range, so if the PC for example was 192.168.1.100 i would go with 192.168.1.105 for the Xbox. And make sure you are not setting the Xbox to DHCP, Static or Manual settings work better and are more stable.
6. the subnet mask, default gateway and DNS servers should match exactly what you wrote down from the ipconfig/all screen.
that is about all there is to it. Other things that can interupt your connaction are:
1. firewalls
2. antivirus programs
3. needing to forward ports for your model of router in order for it to work. which ports to forward can be found at Xbox.com
Ok steimy I did what you suggested... I made sure my firewall wasn't getting in the way of my connection. As far as I know I don't have any anti-virus software on my computer. But I will need to check out the last possible problem you listed the "ports to be forwarded" thing.